It is known to drive various automobile accessory assemblies, including for example a water pump, an alternator/generator, a fan for cooling coolant, a power steering pump, and a compressor, using the vehicle engine. In particular, a driving pulley actuated by an engine shaft of the motor vehicle drives an endless drive belt that in turn drives the accessory assemblies through driven pulleys.
Periodic torque pulses initiated by, for example, combustion engine firing can create significant speed transitions which can interrupt smooth operation of the driven components. In addition, inertial and driven speed transitions associated with startup, shutdown, jake braking, gear shifting, etc. can also interrupt operation of the driven components. These transitions can result in undesirable effects such as belt jump, belt wear, bearing wear, noise, etc.